Pipe plugging device



A ril 16, 1935. P. G. WAGNER PIPE PLUGGING DEVICE Fil ed May 8, 1955 2 Sheets-Sheet 1 E J w *M\ t M mQ I nmnlor Paul 61 Wagner.

flltorney.

April 16, 1935. P. G. WAGNER PIPE PLUGGING DEVICE Filed May 8, 1953 2 Sheets-Sheet 2 VIII/mm I nz/enivr Paul 6'. Wagner.

fl twine Patented Apr. 16, 1935 g l. t t 1 UNI-TED STATES PATENT OFFICE 1,997,878 PIPE PLUGGING DEVICE I Paul G. Wagner, Los Angeles, Calif.

Application May 8, 1933, Serial no. 669,930

' 14 Claims. (01.137-76) This invention relates to devices for plugging ized persons is thus made of sufficient diificulty pipes to form a seal against fluid flow, as when to prevent theft of gas and the attendant possi-' service through the pipe has been temporarily bilities of leakage. A j discontinued. This need arises particularly in .A further object is to provide a plug that'may the case of gas service lines, and is a typical inbe inconspicuously placed within the pipein such. 5:

stance. a manner that the pipe fittings can be replaced,

When tenants move from a house and it .rethus hiding the plug and making it difficult of mains vacant for a period of time, there is the access. This also contributes to safety from possibility of loss of gas by theft since no retampering by wrong-doers.

sponsible occupant can be charged with any These objects are accomp in plugging. 1'0 amount used. There is also the danger from device characteristic of my invention by provid leakage from poor gas cocks or valves which are ing aplug with an expansible body that, by the not completely closed. Leaking gas is not only applicationof longitudinal pressuremay be 9X4- a loss, but it accumulates in. the vacant house panded into gripping contact with the pipe walls;

15- and constitutes a grave potential danger to'indi- The resilient nature of the body enables it to fit 15- viduals subsequently entering, unaware of the exactly the contour of the pipe interior to effect accumulation. For these reasons, it is frequent a perfect seal.' The plug also includes a station-- practice to seal the house service lines inv some ary member, by which the plug may be held, and manner if the house is likely'to remain vacant a rotatable member which, when turned, moves even for a short time. l l p The usual sealing means comprises a shut off This'plu is attached t a setting 11001 adapted disk inserted in a union adjacent the meter, at to turn the rota b e p u member to p best an unsure seal. These disks may. be easily plug 0r contract'it, and also to serve as a handle removed by gas-thieves, or by itinerants, thus for locating the plug a the desired point inthe failing in their purpose and leading both to loss pipe; This t ol comp s s a stationary barrel 2 of gas anda reexposure to the danger of gas acbody and a mo interior shaft, engageable cumulating from open or leaking valves. respectively with the stationary and rotatable In the event of an explosion or other accident p ug e b to p d Contract P resulting from such gas accumulations, it isinwithin the pipe.

3U cumbent upon the gas company to prove that the This engagement of the p i001 seal was actually and properly installed; and it complished by relative rotation of the respective is a difficult burden to overcome the presumption stationary members; and since the plug when of negligence arising from the circumstances. n t p p W u bodily W the setting 13001 Therefore, an object of my invention is to prountil it is pa i pp Contact with vide a sealing device in the formof a plug set the D p e and 50 held fixed, and ads no'othel' 35 well in from accessible joint openings, that will means of holding theplil 0311 be pp the sellprovide an effective and non-leaking seal, and ting 0 1 09111101? be disengaged and Withdrawn also will provide a device such that the plug italone until the plug is properly set in place. self cannot be poorly installed or incompletely HOW t e abov a d ether Objects and advan- 40 set in place so as to leak. The inherent chara e O y invention are accomplished Will be 40 acter of the plug is such that, when set, it neces better understood by reference to the drawings sarily becomes a complete bar to passage. of and'the following description whereinIshow and. fluid, and cannot be left inthe pipe, unless propdescribe typical embodiments of my invention. erly placed, so that negligence or carelessness on n t drawings! I longitudinally to compress or release the body.- 0; v

the part of a workman cannot leave a closure in Fig. is a longitudinal median Section Of y an unreliable condition. Thus, with .a record improved pipe plugging device showing an unexkept that a plug has been set in a given line, there panded plug inserted within a pipe; is prima facie evidence that a proper seal was Fig. 2 is a View similar to Fig; 1 showing the effected and the gas company is relieved of the plug expanded and set in place; p charge of negligence. Fig. 3 is a fragmentary elevation of a plug and 50- It is also an object of my invention to provide one end of the setting tool showing the parts in a plugging device having particular means for the positions occupied as the plug is being atplacing the plug, and without which the plug tached to the tool; cannot be removed, at least except with great Fig. 4 is a view similar to Fig. 3 showing the difliculty. Removal of the closure by unauthorpartsin different positions;

Fig. 5 is a view similar to Fig. 3 but illustrating a variational form of attaching slot on the setting tool;

Fig. 6 is an end view of the setting tool;

Fig. '7 is an end View of a plug;

Fig. 8 illustrates a variational form of plug body and shows a typical placement of the plug;

Fig. 9 is a view similar to Fig. 8 after the plug has been set in position; and

Fig. 10 illustrates another variational form of plug.

The plugging device has two main parts, the plug generally indicated in Fig. l at I0 and the setting tool generally indicated at II. The plug comprises a mandrel in the form of threaded bolt [4 upon which are mounted washers l5 and IE to provide shoulders at either side'of plug body H, which body is formed of rubber or of other suitable resilient and expansible material. These members are loosely mounted upon the bolt so: as to. be free to slideover the bolt threads but limitedby the head of bolt I4 which forms a stop for washer I 5 and body l1. Body I! is preferably tapered or frusto-conical in shape, the largest diameter being substantially the interior diameter ofthe pipe which it is wished to plug, tho this is not essential in certain situations as willbe made: apparent; and washers l5 and I6 are preferably of a diameter slightly less'than the adjacent ends of-the body- Beyond washer l6 iscollar l8 slidably mounted upon bolt 1 4 but held against rotation thereabout by pin l9 which projects'through the collar into keyway 23 cut longitudinally of the bolt. Pin [9 extends for adistance above the periphery of collar l8 so that it may be taken by a member of the setting device andthereby serve as a means to hold the mandrel against rotation,.for reasons that will become apparent. Cylindric nut.22 is threaded onto the bolt adjacent collari8, and theend of the bolt is headed over at Ma to provide a stop shoulder preventing subsequent removal of the nut.

Setting tool H comprises a hollow cylindrical barrel body 24., within the bore 24a of which a. shaft, here in the form of plunger 25, is. capable of rotation and limited longitudinal movement.

One end of barrel 24 is closed by cap .26 which,

after assembly, may be afiixed against; accidental removal by indenting a flange portion into a circular' groove in body 24 as at 2?. Plunger 25 has head portion 2511,. having sliding fit in bore 24a, and'stem portion 28 which has bearing in cap 26-; and the plunger carries at its outer end cross bar 30' that acts as a handle by means of which to. operate the plunger. Pin 28 is surrounded by compression. spring. 3| which bears at opposite ends against head 25: and cap 25 to press the plunger towards the open end of barrel 24, the travel being limited by engagement of cross bar with cap 28'. Fig- 3 indicates'the plungerat the limit; of its travel. As illustrated in Figs, 1 and 6-, the end of plunger head 25a is provided with a central bore 33 adapted to receive, with-clearance, the end of bolt It, and with a stud pin 34, oiT-set from the head axis, adapted to fit within socket in nut 22', as will be more fully explained. For purposes of attaching the plug to thesetting tool, the end of barrel 24 is provided with a T-shaped slot comprising a longitudinally extending entry portion, transverse portion and return portions-Mla. and 40b at oppositeends of portion 40', as illustrated in Figs. 3 and 4,. Return portions 40a and 40b are here shown as defined at points adjacent portion 40 by shoulders 400 over which pin l9 may be cammed in certain situations.

Until the plug is attached to the setting tool, spring 3! normally presses plunger 25 toward the open end of the tool body to the position of Fig. 3. Collar l8 and nut 22 are of a size to slide easily into the bore of body 24 and when this is to be done, the parts are first brought into the position of Fig. 3 with pin IS in registration with open end of slot 40. Although pin 34 is adapted eventually to be received within socket 353 in nut 22, it is probable that the pin and socket are not in initial registration but that the base of [the nut presses against pin 3 1 as shown. By forcing further longitudinal movement of the plug relative to the setting tool, nut 22, by its engagement with pin 34, moves plunger 25 to the right against pressure in spring 3|; and pin I9 moves through slot portion 40 into transverse slot portion 40 when, by a slight rotation .of the plug, pin !9 is moved to one end of said transverse portion. Thereupon spring 3! is allowed to move plunger 25 and plug l0 toward the left (Fig. 4) which movement carries' pin I9 into return slot portion Mia, the plug and setting tool thereafter being held positively against further relative rotation in given directions and being held yieldingly against relative rotation in opposite directions, 1. e., in directions tending to return pin l9' into registry with slot 48. As will be seen, pin 59 will have to be moved longitudinally of tool against the pressure of spring 3|. before it. can be rotated to ride over shoulder 400 into slot portion 40. l g The reason for entering pin [9 in slot 4 1a rather than 40b is that subsequent rotation of nut 22 (necessary to eifect the expansion of the plug, as will be explained) is, prior to the plug actually gripping the pipe, in a direction which, because of the endwise frictional engagement of the nut. and collar l8, would tend to rotate the collar in a manner to bring pin 19 out of slot 491) and into registry with slot 40 to thus allow premature disengagement of the plug from the setting tool. With the pin in slot 40a, the same rotation of the'nut merely tends to rotate collar IS in a directionto bring pin I9 against the closed end of said slot which gives the efiect desired.

With the plug thus attached to the tool, plunger 25 is rotated by handle 30 until pin 34 comes into registry with socket 35 when the pressure of spring 3| is free to further project plunger 25, thus entering pin 34 into socket 35. The parts are now in the position of Fig. 1 ready for insertion into a pipe and the setting of the plug. When the plug is attachedto tool II the setting tool becomes a handle. by means of which the plug may be inserted into the open end of a pipe P and moved toany desired point, limited by the length of barrel 24, in the pipe for preventing flow of fluid there through.

It is to benoticed that plunger 25 is now connected to nut 22 through pint-)4 so that rotation of plunger by handle 30 is adapted to rotate said nut, while barrel 24 is connected to mandrel M, through pin [9 -'so that the barrel may be utilized to hold the mandrel against rotation. Hence, by grasping the barrel in one hand and handle 3B in the other, said barrel and plunger may be rotated relatively to'set up relative rotation of mandrel and nut in a manner which, by virtue of the screw thread connection, sets up relative longitudinal movement between the mandrel and nut.

With a plug of proper size in a pipe (as'in Fig. 1. handle 30 is rotated right-handedly (assuming the mandrel'threads are right handed), and mandrel M is thus drawn to the right (Fig. 2) into bore 33. Washer i5 is also drawn to the right and, because ism-s73 washer l6 isbacked up by collar |8 and nut 22"; applies longitudinal pressure'to resilient body .l 'l;

which pressure causes radial expansion of said body tobring its periphery into firm sealing'conf' tact with the walls 'of, pipe P, as illustrated in Fig.2. At the same time this pressure effectively seals the. joints between body l1, the washers, and the mandrel. Handle 39 is turned until theoper ator determines by the resistance encountered that the plug has been sufiicientlyexpanded radiallyt'o' provide an effective seal against fluid passage within the pipe and to hold the plug against'any movement induced by fluid pressure.

' When the plug is thus set in the pipe, the pres-;

sure of body 'Il'against the pipe walls holds the plug against rotation and longitudinalmovement,

and the setting tool may be quickly and easilydi sengaged fromthe pl'ug'by simply'rotating barrel 24. This rotation is allowed since pin l9 remains stationary, causing shoulder 400 of return slot 48a (Fig; 4) to act as a cam which draws the tool body longitudinally towards the 'plug against the pressure of spring 3!. I Slot portion 40 isthus brought into registry with pin lil fwhereupon spring 3| acts against cap 25 to shift barrel- 24 to the right in Fig. 4 to clear slot 40 from'pin l9 so by straight longitudinal movement.

Consequently the relative rotation between plug and tool necessary to disengage one from the other cannot be setup until suchproper gripishad,

As a result,the fact that the operator'has effected such"disengagement is proof that the plug is An' improperly expanded properly expanded.

e, an obvious'advantorque which may be applied to a set plug by the tool before disengagement of the tool is effected;

Hence, they are determinative of the tightness of the 'plugs grip on the pipe. .By altering either of necessary to clear pin !9 from s'lot 40a, beset up by the cam action of shoulder'dllc. Instead, the too-l barrel may be thrust toward the plug, compressing spring 3!, until shoulder 40c clears pin i9, and the barrel then rotated into register with slot portion 49'. This procedure is necessarily followed in a variation described later.

To remove a set plug, the tool is inserted in the pipe and connected to the plug as described before, except that the barrel is rotated reversely to seat pin IS in return slot lflb'as shown in dotted lines at 2% of Fig. l. This particular seating is chosen because the subsequent rotation of plunger 25 to unscrew nut 22 must be in the opposite di rection from the rotation to compress the plug body, and were the pin seated in slot 4011, such slot} particularly after nut 22 and shoulder [4a engage one another.

1 If 'pinl3 4 is not 'in registry with socket 35, ham-- dle 30 is turned until spring 3| snaps the pin home into the's ocket, whereupon further rotation of the handle in the proper direction rotates nut' 22 in a'm'anner to move mandrel M to the left in Fig.2, thus relieving plug I! of its endwi'se pressure. The inherent elasticity of the plug body causes it tocontract radially and to return to its normal size and shape, permitting its withdrawal from the pipe by straight longitudinal pull] Pressure of spring 3| keeps pin'l 9 in return slot-40b during this withdrawal movement so there is no danger of the plug becoming disengaged from the tool.

l As mentioned, nut 22 is preferably secured by shoulder I'4a against removal from bolt I4 so that in loosening the plug the bolt and nut will not be inadvertently separated, thus leaving the" bolt and plug body in thepipe.

, When the return slot shoulderlflc is in the nature of a cam, as so far described, the plug and :setting tool may be detached by applying a simtion 40. 'The' T-shape of the slut gives one return portion to be utilized when the rotation is in one direction, and'the other return portion when the-rotation is in the other direction, thus giving a closed be'aring face for the pin in either direction of tool rotation;--

However, where the described cam action is not utilized, a variational form of L-shaped slot 42 may be used, as illustrated in Fig. 5. In this instance, the plug'is' made up of entry portion 50,

transverse portion 5l,'and th'e' single return portion 52, bothsi'des of thef'return portion-being of a shape that rotational force applied to thetool body produces no longitudinal component; hence the plug can be separatedrrem the tool bodyonly by positive longitudinal movement of the tool prior to the required rotational movement. Therefore, the 'single'return slot suffices irrespective of the direction of rotation of nut '22 as the sides "of the one 'slot provide closed bearing'faces for thepin, effective in; either direction of tool n a io v. .0

' With either the-T or L form of slot the same principles apply. In both'cases the plug must beiexpandedito at least a predetermined minimum amount of gripping contact with the pipe walls to resist a given disengaging force'applied through the s'ettingtool. In both cases, the resistance to movement by such forces is acquired solely by the friction between the plug and the pipe.

- Fig. 8 illustrates the method of placing the plug through a T, and also illustrates a variational form or shape of plug body 41. It frequently happens that the internaldiameter of a pipe at the end may be reduced by the presence of burrs, as at 48, caused by the cutting off tool when the pipe was cut to length. When such is the case, a plug as nearly approximating'the internal diameter of'the pipe as is illustrated in Fig. 1 will notpass burr 48, so a plug 41 of smaller maximum diameter is preferred. The smaller plug body 4'! inust be expanded a greater distance in proportion to its size, and so the tapering contour of -the body is' somewhat modified to provide an increased-mass of rubber and decrease the amount departing from the means of expansion required. The forward partoi plug body 41 is tapered so as to retain theadvantages of such in guiding the plug intoa pipe opening, and the rear part of the body is made cylindrical of as large a diameter as will go through burr 48. In this manner the mass of the body is somewhat. greater than if it were tapered forwardly from Washer l6 and less compression is required to expand the plug into gripping contact with the pipe walls. By placing the plug beyond burr 48 as in Fig. 9-, a better seal is obtained than if the burr wereindented into the plug body.

The-forms above described have been of such a size as to pass through the'pipe in order that they may be set anywhere in the pipe within the working range of a given setting tool (which tool maybe of any desired length), and preferably somewhat distant from the end of the pipe to make them less conspicuous and to make ;the removal more difficult, if not impossible, except by means of the same tool with which the plug was set in place. In Fig. 10, there is illustrated a modified form in whichwasher l6a is enlarged so that it exceeds the internal diameter of the pipe to be plugged. In this manner. the plug may .be definitely positioned at the end of the Having described certain embodiments of my invention, it is to be realized that the drawings and the foregoing description are to be considered as'illustrative of rather than restrictive upon broader claims appended hereto, for vari-' ous changes in form and arrangement of parts may be made by those skilled in the art without spirit and scope of said claims.

I claim: 1. A pipe plugging device comprising an expa'nsible plug adapted, in its contracted condition, to beinserted within a pipe and then to be expanded into fluid tight engagement with said pipe, a tool for so inserting and then expanding. the plug, said tool being detachably connected to said plug, and means preventing unintentional detachment of the tool from the plug after insertion of the plug into the pipe, until said plug. is expanded into fluid tight fit with the pipe.

2. A pipe plugging device comprising an expansibleuplug adapted, in its contracted-condition, to be inserted within apipe and then to be expanded within said pipe, a tool forso inserting and then expanding the plug, said tool being detachably connected to said plug .by relative rotation thereof in given directions, and preventing reverse" relative rotation thereof and thereby preventing unintentional detachment of the tool from the plug. after insertion of the plug into the pipe, until said plug is expanded a predetermined'extent.

3. A pipe plugging device comprising a plug adapted to be expanded into gripping contact with a pipe interior, a tool for expanding the plug in place, and releasable means foroperativelyconnectingthe plug, to hold the plug and tool against relative rotation; said releasable means comprising a pin, a pin seat, and pin seating means, said seating means releasing the pin from the seat when a torque in excess of a predetermined value is appliedby the tool to the plug when expanded into engagement with a pipe interior.

4. A pipe plugging device comprising a plug adapted to be expanded into gripping contact with a pipe interior, a tool for expanding the plug in place, and releasable means for attach-- ing the plug tothe tool; said attaching means comprising a pin on the plug, a. pin receiving slot having a cam shoulder. on the tool, and a spring resiliently holding the pin in the slot and against movement over said cam shoulder.

5. A pipe plugging device comprising a plug adapted. to be expanded into gripping contact with a pipe interior, a tool for expanding the plug. in place, and. releasable means for attaching the. plug. to the tool to hold the plug and tool against relative rotation; said releasable means comprising a pin, a pin seat, and yieldable pin sea-ting means, said seating means yieldingto unseat the pin under a longitudinal force inexcess of a predetermined value applied by the tool to the plug. when expanded into engagement. with a. pipe interior.

, 6, A pipe plugging device comprising a plug adapted to be expanded into gripping contact with a pipe interior, a tool for expanding. the plug in place, and means including a pin and a pinconfining slot for releasably attaching the plug to the tool, said pin being releasablefromv the slot-when the expanded plug offers a predetermined resistance to movement.

7 Apipe plugging device comprising a plug embodying a radially expansive, tubular body, a threaded mandrel within the bore of the body, a shoulder on the mandrel at one end of the body, a nut threaded on the mandrel. at the other end of thegbody and movable along the mandrel toward the shoulder to compress the body longitudinally and thus expand it radially, and a memberslidable along but non-rotatably mounted onthe mandrel; and a setting tool to expand the body into contact with the pipe, said tool comprising a: member engageable with said non-rotatable plug member to hold the latter against rotation, and a second member engageable with said nut for imparting rotation thereto.

8. A pipe plugging device comprising a plug embodying a radially expansive, tubular body, a threaded mandrel within the bore of the body, a shoulder'on the mandrel at one end of the body, a nut threaded on the mandrel at the other end of the body and movable along-the mandrel toward the shoulder tocompress the body longitudinally and thus expand it radially, and a member slidable along but nonrotatably mounted on themandrel; and asetting tool to expand thebody into contact with the pipe, said tool comprising a barrel engageable with said non-rotatable plug member to hold the latter against rotation, and a shaft movable within the barrel and engageable with said nut for imparting rotation thereto.

9. A pipe plugging device comprising a plug embodying a radially expansive, tubular body, a threaded mandrel within the bore of the body, a shoulder on the mandrelat one end of the body, anut threaded on the mandrel at the other end of the body and movable along the mandrel toward the shoulder to compress the body longitudinally and thus expand it radially, and a member slidable along but non-rotatably mounted on the mandrel; and a setting tool to expand the body into contact with the pipe, said tool comprising a barrel engageable with said non-rotatable plug member to hold the latter against rotation, and a shaft rotatable within the barrel and engageable with said nut for imparting rotation thereto, said shaft being movable longitudinally within the barrel to effect engagement of said tool members with said plug members.

10. A pipe plugging device comprising, a plug embodying a radially expansive, tubular body, a threaded mandrel within the bore of the body, a shoulder on the mandrel at one end of the body, a nut threaded on the mandrel at the other end of the body and movable along the mandrel toward the shoulder tocompress the body longitudinally and thus expand it radially, and a member slidable along butnon-rotatably mounted on the mandrel; and a setting tool to expand the body into contact with the pipe, said tool comprising a barrel engageable with said nonrotatable plug member to hold the latter against rotation, a shaft rotatable Within the barrel and engageable with said nut for imparting rotation thereto, said shaft being movable longitudinally within the barrel to effect engagement of said tool members with said plug members, and a spring in said barrel urging the shaft toward the plug.

11. A pipe plugging device comprising a plug embodying a radially expansive, tubular body, a threaded mandrel within the bore of the body, a shoulder on the mandrel at one end of the body, a nut threaded on the mandrel'at the other end of the body and movable along the mandrel toward the shoulder to compress the body longitudinally and thus expand it radially, and a member slidable along but non-rotatably mounted on the mandrel.

12. A pipe plugging device comprising a plug embodying a radially expansive, tubular body, a threaded mandrel within the bore of the body, a

shoulder on the mandrel at one end of the body, a nut threaded on the mandrel at the other end of the body and movable along the mandrel toward the shoulder to compress the body longitudinally and thus expand it radially, and a member slidable along but non-rotatably mounted on the mandrel, said slidable member including a collar and a pin projecting beyond the periphery of the collar and also into a keyway in the mandrel.

' 13. A pipe plugging device comprising a plug adapted to be expanded into gripping contact with a pipe interior, a, tool for expanding the plug in place, and releasable means for attaching the plug to the tool; said attaching means comprising a pin on the plug, a T-shaped pin receiving slot in the tool, a cam shoulder at each end of the transverse portion of the slot, and a spring resiliently holding thepin in the slotand against movement over a selected cam shoulder.

14. A pipe plugging device comprising a plug adapted to be expanded into gripping contact with a pipe interior, a tool for expanding the plug in place, and releasable means for attaching the plug to the tool; said attaching means comprising a pin on the plug, an L-shaped pin receiving slot in the tool, said slot having an entry portion, a transverse portion, and a return portion, and a spring resiliently holding the pin in the return portion of the slot and against movement longitudinal of the tool.

PAUL G. WAGNER. 

